Sound reproducing system



B. G. WEST ETAL SOUND REPRODUCING SYSTEM May 13,1941.

3 Sheets-Sheet I' N w wk nab Filed Feb. 11,- 1959 w w E r wfimm w aw 0 0m m E0 5 A? E #4 A m H 5m x 3 k m g r IIW kw w m9 @Q u Ma Q 3Sheets-Sheet 2 4 420 6. W55; M120 4. W557 #420 2290/1/05 I INVENTORS.ATTORNEY.

B. G. WEST ETAL SOUND REPRODUCING SYSTEM Filed Feb 11, 1939 May .13,1941. a. G. wr-:s"r EI'AL SOUND REPRODUCING SYSTEM 3 Sheets-Sheet 3Filed Feb. 11, 1939 552M420 6. W557 I w W m Patented May 13, 1941 UNITEDSTATES PATENT OFFICE SOUND REPRODUCING SYSTEM Bernard G. West, LeonardA. West, and Richard T. Pounds, Long Beach, Calif., assignors, by mesneassignments, to Jesse '1. West, trustee Application February 11, 1939,Serial No. 255,884

22 Claims.

Our invention relates to a sound reproducing system and has particularreference to a coin actuated system for reproducing phonographicrecordings.

Coin operated phonographic reproducing devices are commonly employed inrestaurants,

cocktail bars, and like establishments as a means reproducing equipmentand coin collecting mech-,

anism but a mechanical recording-selecting device which is responsive tocomplicated controlling mechanism for causing the reproduction of theone of the ten or fifteen selections available which was chosen by. theperson placing the device in operation. Furthermore, the number ofmusical selections available for choice is quite limited so that theselection desired by a customer is oftentimes not available with theresult that the machine is not operated to the extent that it would bewere there a wider selection of recordings available.

When devices of this type were introduced they became at once verypopular because ftheir novelty. As soon, however, as this novelty woreoff the above mentioned disadvantages began to predominate and thecollections made by the devices reduced to a fraction of their initialvalue.

It is therefore an object of our invention to provide a. coin actuatedsound reproducing system in which a great number of recordings areavailable for selection.

It is a further object of our invention to provide a. coin actuatedsound reproducing system including controlling devices and reproducingequipment operating in such a novel manner that a customer's interestmay be held over long periods of time.

It is also an object of our invention to provide a coin actuated soundreproducing system in which all of the phonographic recordings em-'ployed and all of the reproducing devices used therewithare disposed ata centrally located central station and connected to a. plurality ofremotely located control stations, each of which includes a soundproducing device for reproducing at the control station the materialrecorded on a phonographic recording at the central station and a coincollecting device for placing the system in operation.

It is also an object of our invention to provide a coin actuated soundreproducing system of the character set forth in the precedingparagraphs in which an indicating means is provided at the centralstation for indicating to an operator the insertion of a coin at any oneof the remotely located control stations.

It is an additional object of our invention to provide a soundreproducing system of the character set forth in the precedingparagraphs in which the indicating means is actuated to inform theoperator which station collected the coin and the value of the coincollected.

It is an additional object of our invention to provide a coin actuatedsound. reproducing system of the character set forth in the precedingparagraphs in which the indicating means operates to indicate thedifference in value between the coins collected and the number ofrecordings reproduced at the control station and in which a registeringdevice is employed to register the total value of coins collected ateach control station. 7

It is a further object of our invention to provide a sound reproducingsystem of the character set forth in the preceding paragraphs in which aloud speaking, two-way telephone circuit is completed between thecontrol and central stations upon the insertion of a coin in the controlstation coin collecting device so that a person desirous of hearing aparticular recording reproduced at the control station may transmit hiswishes to an operator at the central station.

It is also an object of our invention to provide a coin actuated soundreproducing system of the character set forth in the precedingparagraphs in which indicating means is provided at the central stationfor indicating the value of the coins collected at any control stationand cooperating with a phonographic reproducer associated with thatstation for deducting from the amount so indicated the value of therecordings reproduced at said control station.

It is also an object of our invention to proto the central station thevoice of a customer and the value of the coins collected at the controlstation.

Itis a further object of our invention to provide a sound reproducingsystem of the character set forth in the preceding paragraphs in which asound producing device and a sound responsive device are employed at thecontrol station, together with means interconnecting said devices to asingle pair of wires extending to the central station in such mannerthat sound received by the sound responsive device is transmitted to thecentral station without being reproduced by the sound reproducingdevice, while sound transmitted from the centralstation to the controlstation over the same pair of conductors is reproduced by the soundreproducing device.

Other objects and advantages of our invention will be apparent from astudy of the following specifications, read in connection with theaccompanying drawings, wherein:

Fig. 1 is a schematic wiring diagram illustrating the electricalconnections and the equipment employed at a central station and at eachof a plurality of control stations and illustrating the interconnectionsbetween the central station and ployed at a control station;

Fig. 2 is a perspective view illustrating the appearance of one form ofa remote unit em ployed at a control station;

Fig. 3 is a plan view illustrating the relative locations of theequipment employed at a central station;

Fig. 4 is a fragmentary elevational view taken substantially along theline IV-IV of Fig. 3 illustrating the appearance of a portion of theequipment employed at the central station and illustrating the detailsof construction of a record filing rack;

Fig. 5 is a fragmentary sectional view taken substantially along theline V--V of Fig. 4 to illustrate additional details of construction ofthe record filing rack;

Fig. 6 is an elevation illustrating the relativelocations of certaincontrol equipment employed on control panel located at the centralstatron;

Fig. '7 is a rear view of a coin indicating and registering mechanismwhich is employed as one of the units incorporated in the control panel,Fig. '7 being taken substantially along the line VII-VII of Fig. 8;

Fig. 8 is an elevational view illustrating addiiional details ofconstruction of the coin indicating and registering mechanism; and

Fig. 9 is a fragmentary elevational view taken substantially along theline IX--IX of Fig. 8 illustrating the details of construction of a camactuated switch mechanism employed on the coin collecting andregistering mechanism.

We have illustrated in the accompanying drawings the preferredembodiment of the sound reproducing system of our invention as includinga, central sound reproducin station which is operatively connected to aplurality of outlying control stations, six of these control stationsbeing shown in Fig. 1 for the purposes of illustration. Briefly stated,the system of our invention provides equipment at the central stationwhich is responsive to the insertion of a coin in any one of a pluralityof coin collecting devices located at each of the control stations forapprising a central station operator of the fact that a customer at thatcontrol station is desirous of hearing a phonographic recordingreproduced for his pleasure. In response to the signal transmitted tothe central station, the central station operator inquires by means of atwo-way loud speaking telephone circuit which extends between thecentral station and the control station the number or title of theparticular phonographic recording which the customer is desirous ofhaving reproduced. This information is relayed by the same telephonicsystem from the customer to the central operator who then operatesreproducing equipment located at the central station to causereproduction at the control station of the desired phonographicrecording.

The equipment which comprises each of the control stations isconstructed in the preferred embodiment of our invention along the linesillustrated in Fig. 2 and includes a housing or cabinet l which isprovided in its front face with a loud speaker grill 2 behind which isconcealed a signal receiving means which may comprise a suitable soundproducing or loud speaking device (not shown) adapted to convertelectrical undulations to corresponding sound undulations. The loudspeaker may be of any well known type and equipment (not shown) foramplifying relative- 1y weak signals transmitted to the unit from thecentral station to a sufiicient intensity to provide the desired volumeof reproduction from the loud speaker.

The equipment is placed in operation by a customer at any one of thecontrol stations operating a signal producing means as by placing a coinin a conventional coin collecting mechanism 3 which may be mounted onthe front side of the cabinet I in a readily accessible position. Priorto placing the equipment in operation, the customer chooses from anindex or catalogue which may be disposed behind a transparent upperpanel 4 in the cabinet I the particular phonographic recording he wishesto hear reproduced. In order that the customer after having placed theequipment in operation may convey his desires to the central stationoperator, we provide a.microphone or sound responsive device5 mounted inany convenient location in the cabinet I which will receive the soundundulations from the customer's voice and operate to transmitcorresponding electrical undulations to the central station.

The equipment which is provided at the central station is preferablyarranged, in the preferred embodiment of our invention, in the fashionillustrated in Fig. 3. This arrangement includes a U or C shaped table 6including a central control section Go and right and left wing sections6b and 60.

equipment associated with the phonographic reproducers 10 may be mountedin an amplifier rack indicated generally at l2 in Fig. 3.

One of the outstanding advantages to. be derived from the use of thesystem of our invention resides in the ability to provide a very largenumber of phonographic recordings from which the customer may choose. Weaccordingly dispose above each of the wing sections 6b and 6c a rack orfiling case for storing a large number of phonographic recordings orrecord tablets. These racks are preferably constructed as illustrated inFigs. 4 and 5 and comprise a pair of longitudinally extending railmembers l3 and M which are supported upon a shelf member |5 carried aconvenient distance above the top of the table sections 6b and 60 bymeans of supporting legs l6. We provide a plurality of partitions IIwhich extend upwardly and between each of the rails l3 and I4. Each ofthe partitions H are placed in a position closely adjacent adjoiningpartitions I! so as to provide narrow spaces or bins therebetweenadapted to receive in an edgewise fashion one of the record tablets 9.Indexing of the multiplicity of the record tablets 9 filed in thisfashion may be obtained by providing suitable numbers or indiciainscribed on the face of the front rail l3 in a position disposeddirectly below the particular tablet 9 to which such indicia refers. Byfiling the record tablets 9 in this closely adjacent, edgewise fashion avery large number of record tablets may be stored and indexed in a smallspace in such manner that any selected one of these record tablets maybe readily found and removed from its rack and placed upon one of theturn tables 8.

In order that the central station operator may have complete control ofthe central station equipment, we provide on the control section Go ofthe table 6 a control panel |B which may be constructed along thelinesindicated in Fig. 6. The control panel illustrated in Fig. 6includes an upper section HI and a lower section 20. We prefer toincorporate in the upper section IS the equipment which is associatedwith each of the remotely located control stations andaccordingly dividethis section into six sub-sections 2|. Each of the sub-sections 2|carries a warning light 22, the illumination of which is employed toinform the central station operator that a customer at the controlstation corresponding to that light is desirous of having a phonographicrecording reproduced at his station.

The coin collecting devices which are employed at the control stationsare preferably adapted to collect three different sizes of coins, in thepreferred embodiment of our invention, nickels, dimes, and quarters. Inorder that the central station operator may be informed of the value ofthe coin inserted in the coin collecting mechanism, we provide a signalreceiving means comprising an indicating device 23 which includes ascale 24 and a pointer 25 adapted to move over the graduated scale 24.The scale 24 is preferably graduated in units which correspond to thevalue of a nickel so that if the pointer 25 has moved up one division,the central operator will know that a nickel has been inserted in thecoin collecting mechanism, and that if the pointer 25 has been moved uptwo or five divisions, 'she will be informed that a dime or a quarter,respectively, has been inserted in the coin collecting mechanism.

Each of the sub-sections 2| also carries 9. volume control unit 26 whichwe connect in circuit with the associated reproducing unit Ill so thatthe sound level in the circuit connecting with the control station maybe adjusted and observed on a volume indicating device 21 which ismounted on the lower panel section 20. The lower section of the panel isalso provided with a rotary switch or selector means 28 which includes acontrol knob and pointer 29 adapted to be moved in a rotary fashion overa scale 30. The scale 30 carries a number of graduations representingcontrol connections which may be established by the selector means 28,the number of such connections being made equal to the number of controlstations employed with the system of our invention.

The selector means 28 is employed in a man nor to be describedhereinafter to connect certain central station controlling equipment toany one of the units located at the various control stations, thisequipment including a signal producing means for acknowledging thedeposit of a coin, shown herein as comprising a microphone 3| into whichthe central operator may speak in order to inquire of the customer atthe calling control station the particular phonographic recording hewishes to hear reproduced and which.

may also be used for verifying the indicia employed to refer to suchphonographic selection.

In order that the microphone 3| may be left normally out of the circuitto the control station selected by the selector means 28, we provide athree-position transfer switch 32 which is adapted to be manually movedinto any one of three available positions so that the microphone 3| maybe cut into the circuit to the selected control station for the purposesset out hereinbefore or so that a monitor loud speaker (not shown)mounted in the amplifier rack I2 may be connected through a volumecontrol unit 33 to said control station or so that said monitor loudspeaker may be connected through another volume control unit 34 to theselected control station, the volume control units 33 and 34 servingdifferent purposes as will be explained in detail hereinafter.

The manner in which the monitor speaker and the other above describedapparatus. is employed in the operation of the system may best beunderstood by having reference to the schematic wiring diagram (Fig. 1).In Fig. 1 we have enclosed in dashed lines indicated by the referencecharacter 35 all of the equipment located at the central station, whileeach of the six control stations are indicated by the referencecharacter We have illustrated also in Fig. 1 the electrical connectionsand the equipment employed at one of the six identical control stations,this equipment being illustrated in Fig. 1 as enclosed in dashed lines36. Power for the operation of the control station equipment may bederived from any suitable available Iocal'source of power and connectedto the equipment mounted within the cabinet I by means of conductors 31and 38.

In order to describe the manner in which the previously describedequipment operates, we will assume certain operating conditions anddescribe the manner in which the equipment operates under these assumedconditions. Let us assume therefore that the control station equipmenthas been connected to a suitable source of power through conductors-31and 38 and that the customer at the control station has placed theequipment in operation by inserting a coin in one of the coin receivingapertures in the coin collecting mechanism 3.

The coin collecting mechanism 3 is of any one of a number of well knowntypes and includes electrical switchcontacts 39 which are maintainednormally in an open circuit position but which cooperates withassociated mechanism to close their circuit momentarily a number oftimes which is equal to the number of nickels represented by the coininserted in the coin collecting mechanism. In other words, the equipmentassociated with the contacts 39 is so arranged that should a nickel'beinserted in the.

assigned coin receiving aperture, the contacts 39 will be momentarilyclosed once but if a dime or a quarter is inserted, these contacts willbe closed momentarily two times or five times, respectively.

The operation of inserting a coin in the coin collecting device 3 mayapprise the central operator of the fact that a customer is desirous ofhearing a phonographic recording reproduced at the control station andthe monetary value of the coin collected by the coin collecting devicemay also be indicated to the central station operator by connecting theswitch 39 by means of conductors 40 and 4| between the power supplyconductor 31 and one of a pair of line conductors 42 and 43 which extendfrom the control station to the central station so that insertion of acoin in the coin collecting device 3 will cause' the line conductor 42to be energized momentarily a number of times which is equal to thenumber of monetary value units included in the coin inserted in the coincollecting device and by connecting one side of a relay coil 44 betweenthe line conductor 42 and ground by means of conductors 45 and 46. Thusthe relay 44 may be momentarily energized and deenergized a number oftimes which is equal to the number of monetary value units in the coincollected by the coin collecting device.

This operation of the relay may be caused to register on the indicatingdial the appropriate number by grounding the supply conductor 38 andextending a conductor 41 between a normally open contact of the relay 44and a solenoid 48 of the indicating mechanism 23 and by grounding,through a conductor 49, the other terminal of the solenoid 48. Power mayin this fashion be supplied through the normally open contacts of therelay 44 to the solenoid 48 by connecting said normally open contactsalso to a control bus 50 which is connected to the ungrounded line of asuitable central station power supply indicated in Fig. 1 generally atThe manner in which the energization of the solenoid 48 causes a numberof monetary value units included in the coin collected by the coincollecting device 3 to be indicated on the dial 24 may best beunderstood by having reference to Figs. 7, 8 and 9 which illustrate thedetails of construction of the indicating device 23. This mechanismpreferably includes a frame 52 which is adapted to be secured to therear side of one of the sub-sections 2| of the control panel I8 andincludes a dial shaft 53 adapted to protrude through the panel andreceive the pointer 25. The dial shaft 53 may be journaled for rotationin suitable apertures provided in the supporting plate 52 and a bearingbracket 54 disposed to the rear of the supporting plate 52 and securedthereto.

We non-rotatably secure to the dial shaft 53 a toothed wheel or a gear55 in a position disposed between the supporting plate 52 and thebearing bracket 54. The solenoid 48 is preferably supported upon a shelfmember 56 secured to the supporting plate 52 and disposed below thetoothed wheel 55 so that an armature 51 of the solenoid 48 may rise fromthe solenoid and pass the toothed wheel 55. The armature 51 is providedat its upper end with an adjusting nut 58 which cooperates with acompression spring 59 restrained between the adjusting nut 58 and theupper surface of the bearing bracket 54.

The spring 59 is arranged to normally urge the armature 51 upwardly andmove the armature 51 into its uppermost position when the solenoid 48 isde-energized. The spring 59 is made of such strength that theenergization of the solenoid 48 will overcome the effect of the spring59 and move the armature 51 downwardly. The armature 51 carries a springmember 60 which is adapted to operate as a pawl relative to the toothedwheel so that energization and subsequent de-energization of thesolenoid 48 causes the spring 59 to rotate the toothed wheel 55 adistance corresponding to one tooth thereof through engagement therewithof the spring member 60. We provide a detent or indexing spring 6| forholding the toothed wheel 55 in its last operated position.

It will be observed that since the solenoid 48 is energized and thende-energized in the manner previously described a number of times whichis equal to the number of monetary value units included in the coincollected by the coin collecting means 3, the dial shaft 53 and thepointer 25 carried thereby will be moved around an equal number ofnotches to cause the pointer 25 to indicate on the scale 24 the numberof such monetary value units collected.

We prefer to warn the central operator in a forceful manner that a coinhas been inserted in the coin collecting device and for this purpose weemploy the previously mentioned warning light 22. The warning light 22may be connected in a circuit between the control bus 50 and groundthrough a cam operated switching device 52 which is incorporated as apart of the indicating device 23 and which may be provided by extendingthe dial shaft 53 through the bearing bracket 54 and mounting on therearward end thereof a segment wheel or cam member 63. The cam member 63is connected to ground by any suitable means such as by grounding thesupporting plate 52 and is arranged to contact a spring switch finger 64as soon as the dial shaft 53 has been moved one notch from its oif"position. The spring switch member 64 is accordingly mounted in anysuitable manner upon an insulating block 65 which is in turn carried byan angle bracket 65 secured to the bearing bracket 64.

By providing an indicating mechanism of this type, the. central stationoperator may be instantly apprised of the fact that a coin has beencollected by the coin collecting mechanism and the monetary value of thecoin collected. It will be further observed that this indicating andwarning mechanism operates not only to relay this information to thecentral station operator, but operates also to inform her which one ofthe siX control stations is calling. The central station operator mayreadily recognize which of the control stations is calling since each ofthe warning lights 22 is associated with but one of the control stationsand the position of one of the lights 22 on the control panel [8relative to the others is representative of the associated controlstation.

As soon as the operator is apprised of the fact that a coin has beencollected by the coin collecting mechanism 3, she may respond to thecall by turning the rotary switch 28 to a position corresponding to thecalling control station.

This will establish the required connections to place her microphone 3]in connection with the loud speaking device included in the controlstation equipment so that her request that the customer announce thenumber or indicia referring to the desired phonographic recording willbe transmitted to the customer.

As illustrated in Fig. 1, we accordingly connect the microphone 3| bymeans of a pair of conductors B1 and 68 to the input of a microphoneamplifier 69. Power for operation of the amplifier 69 may be obtainedfrom the previously described control bus 50. One of the outputterminals of the amplifier 69 may be connected to ground by means of aconductor and the other terminal may be connected by conductors 1| and12 to one of the movable blades 13 of the threeposition switch 32through an isolating condenser 14 so that speech sounds emitted into themicrophone 3| will cause a corresponding voltage to be amplified by theamplifier 69 and applied between the blade 13 and ground.

We assign the first position of the three position switch 32 to thetransmitting or talk position and accordingly connect the contactterminal corresponding to the first position by means of a conductor 15to a wiper arm 16 of the first level of the selector means 28. As soonas the operator turns the selector means 28 to a position correspondingto the calling control station, connection will be established by thewiper arm 16 between the conductor 15 and a conductor 11 connecting aselector contact located at that switch position to the input terminalof a reproducing line amplifier 18, the other input terminal of which isgrounded by means of a conductor 19. Power for the operation of thisamplifier may likewise be derived from the control bus 50.

The output terminals of the amplifier 18 are connected by means ofconductors 80 and 8| to the primary winding of a line transformer 82,the secondary of which is arranged to have its midpoint grounded and oneof its end terminals connected to the line conductor 43 while the otherend terminal is connected to the line conductor 42.through' an isolatingcondenser 82a. In this fashion speech sounds emitted by the centralstation operator into her microphone will cause corresponding electricalundulations to be amplified by the microphone amplifier 89 and by thereproducing amplifier 18 and applied to the line conductors 42 and 43over which such amplified undulations control station unit I.

In order that these electrical undulations may be reproduced as sound inthe presence of the customer who placed the equipment in operation, weconnect the line conductor 43 to one terminal of the primary winding ofa line transformer 83 and the conductor 42 to the other primary terminalthrough an isolating condenser 83a. The isolating condensers 82a and 83aare chosen of such capacitance as to isolate the conductor 42 fromground as regards direct current and low frequency alternating currentto permit operation of the coin indicating device in the mannerdescribed while providing a low impedance circuit through thesecondensers for currents of voice frequency. The secondary winding of thetransformer 83 preferably has its midpoint grounded and one of its endconnections extended by means of a conductor 84 to an isolatingcondenser 85. The other side of the isolating condenser 85 may beconnected by means of a are transmitted to the' conductor 86 to one endof the resistance member comprising a volume control potentiometer 81'.The other terminal of the resistance portion of the potentiometer 81 maybe connected to ground through a conductor 88 and a volume controllimiting resistor 89, while the wiper arm of the potentiometer 81 may beconnected by means of a conductor 90 to the input of a control stationamplifier 9|, the output terminals of which are connected by means ofconductors 92 to a loud speaking device 93. Power for the operation ofthe amplifier 9| is preferably derived from the power conductors 31 and38.

It will be observed that speech currents which are transmitted by theline conductors 42 and 43 to the line transformer 83 will causecorresponding speech voltages to appear between the conground. Thesevoltages will be transmitted through the isolating condenser 85 and thevolume control potentiometer 81 to the input of the amplifier 9|,amplified thereby and reproduced as sound by the sound producing device93. The sound volume may be adjusted by means of the volume control unit81, the volume control limiting resistor 89 being employed to establisha minimum sound level below which it is impossible to attenuate thereproduction, thus preventing inadvertent incapacitating of the controlstation -by reducing the sound level to an inaudible value.

It will be observed that this equipment operates to reproduce as soundin the presence of the person who placed the equipment is operation astated inquiry by the central operator, such as number please" referringto the number or indicia representative of the particular phonographicrecording that person wished to hear reproduced.

Themicrophone 5 which is provided at the.

' conductor 95 and the other terminal by means of the arm portion of abalencing potentiometer 91. One end of the resistance portion of thepotentiometer 91 is connected by means of a conductor 98 to one terminalof the secondary winding of the line transformer 83, the other end ofthe resistance element of the potentiometer 91 being connected by meansof a conductor 99 to the previously described conduotor 86 which feedsthe input of the control station amplifier 9|.

Attention is called to the fact that alternating current voltagescorresponding to sounds emitted in the microphone 5 are impressedbetween the conductor 96 and ground and that after passing through theresistance portions disposed on either side of the movable arm of thepotentiometer 91 then appear between the conductors 98 and ground andbetween conductors 99 and ground.

As previously stated, the conductor 99 is connectcircuit of the controlstaapparent that voltages which are impressed by the microphone 5 onconductors 9t and 99 will both be applied to the input circuit of thecontrol station amplifier 9| but oppositely in polarity relative to eachother. By adjusting the position of the arm portion of the potentiometer91 relative to the resistance portion thereof, these voltages may alsobe made to correspond in magnitude so that the voltages impressed on theinput of the control station amplifier 9| over these two circuits willbe canceled out. It follows then that speech voltages generated by themicrophone 5 will cause corresponding voltages to appear across the linetransformer 83 but will not cause any of the sounds emitted inthemicrophone 5 to be reproduced by the amplifier 9| and its associatedloud speaker 93. Speech voltages thus impressed across the secondary ofthe transformed 83 will cause corresponding voltages to be transmittedto the central station over line conductors 42 and In order that thesespeech voltages may be reproduced as sound in the presence of thecentral operator, we connect a control wire I to the conductor 8! whichis connected to the line transformer 82 so that speech voltagesappearing between the line conductors 42 and 43 will, in this fashion,be also impressed between the conductor I00 and ground. The conductorI00 is accordingly extended and connected to the contact point on thesecond level of the selector switch 28 which is representative of thecalling control station, so that a wiper arm IOI of this second levelwill be placed in contact with the conductor I00 when the switch ismoved to the corresponding position as previously described.

We have arranged the equipment in such manner that the speech voltagesappearing between the conductor I00 and ground are reproduced as soundin the presence of the central operator by means of a monitor loudspeaker I02 which is connected to the output of a monitor amplifier I03as by means of conductors I04 and I05. Power for the operation of thisamplifier is also derived from the control bus 50. The monitor amplifierI03 preferably has one of its input terminals grounded as by means of aconductor I 06 and the other input terminal connected by means of aconductor I01 to a second blade member I08 of the three-position switch32. Whenever the central station operator wishes to hear the voice ofthe customer at the control station, she moves this switch to its secondposition. We accordingly connect a conductor I09 between the secondterminal associated with the blade I08 and a wiper arm portion of avolume control potentiometer 33 whose resistance portion is preferablyconnected between ground and a conductor i I I which connects through avolume control limiting resistor I I2 to another conductor I I3 which isin turn connected to the wiper arm IOI of the selector switch 28. Itwill be seen that -this circuit provides a connection between theaforementioned control conductor I00 and the input of the amplifier I03and includes therein the volume control unit 33 so that the operator mayemploy the volume control 33 to adjust the volume of reproduction of thecustomer's voice to suit her requirements.

As soon as the central operator obtains from the customer the number ofthe phonographic recording desired, she then removes this record tabletfrom its rack, places it on the turn table which is associated with thecalling station, starts the rotation of the record tablet and places thestylus of the reproducing device I0 at the start of the record.

The reproducing device I0 preferably has one of its terminals connectedto ground by means of a conductor H4 and its other terminal connected bymeans of conductors H and IIS through a frequency equalizing pad II! toits associated volume control unit 26. The frequency equalizing pad I Ilmay be adjusted in any suitable manner, but in the preferred embodimentof our invention is arranged to attenuate the high frequencies jtoprovide a compensation for the inherent attenuated low frequencycharacteristics of standard phonographic recordings and reproducingdevices. The volume control unit 26 is preferably connected between theconductor H6 and ground so that variations in its resistance willoperate to vary the potential between conductor H6 and ground.

The conductor H6 is preferably connected to the input of the previouslydescribed reproducing amplifier I8 through a coupling resistor I I8which is connected to the speech transmission conductor 11 and operatesto effectively isolate this c'onductor from the volume control unit 26so that adjustment of the volume control 26 will have little or noeffect upon the volume level of speech sounds transmitted to the lineconductors 42 and 43 from the central station microphone 3|.

The alternating voltages corresponding to material recorded on thephonographic recording will, in this fashion, be amplified by theamplifier I8 and transmitted over the line conductors 42' and 43 and bereproduced as sound by the control station amplifier BI and itsassociated loud speaker 93.

We also provide a means which permits the central station operator tomonitor the reproduction effected by the reproducing device I0 and forchecking the volume level of the transmitted reproduced material. Weprefer that this be accomplished by moving the three-position switch 32to its third position. We accordingly connect the contact terminal whichis engaged by the blade I08 thereof in its third position by means of aconductor II9 to the wiper portion of the volume control potentiometer34. The volume control potentiometer 34 is connected between ground andthe previously described conductor III so that voltages which aretransmitted from the output of the reproducing amplifier I8 throughconductor I00 and the selector means 28 may be transmitted through thevolume control potentiometer 34 to the input of the monitor amplifierI03 to cause reproduction of the recorded material by the monitor loudspeaker I02. We prefer to ground the unused contacts of thethreeposition switch 32, such as the first contact associated with bladeI08 and the second and third contacts associated'with the blade 13, sothat the grid circuits of the various amplifiers associated with theswitch 32 may always be provided with a ground return to insure stableoperation of these amplifiers.

Since the volume level of the communications from the control stationare much lower than the level of the phonographic reproduction, theprovision of independent volume controls 33 and 34 for the respectiveoperations of listening to communications from the control station andfor monitoring the reproduction of the phonographic volume level of thereproduced material may be checked by the central operator havingreference to the volume indicator 2! which may be of a well known typeand connected between the input conductor H3 and ground.

We prefer to adjust the various amplifiers and associated equipment insuch fashion that the actual signal level transmitted over the lineconductors is as low as, or lower than the Signal levels employed in thestandard telephone circuits. This low level transmission permits theemployment of a pair of wires included in a multi-pair telephone cablefor the line conductors 42 and 43 and permits the use of the remainingcable pairs for standard telephonic service without interference orcross-talk." While higher signal levels may be employed if desired, weprefer to operate the equipment at the relatively low transmission leveldescribed, since cable pairs may be leased from a telephone company iftheir requirements are met and thus the high expense of providing longline conductors may be avoided.

In addition to the foregoing control mechanism, we provide a means forautomatically deducting from the number of monetary value units which isregistered by the indicating device 23 a number of monetary value unitswhich is equal to the number of complete phonographic recordings thathave been reproduced at the control station since the insertion of thelast coin. For this purpose we employ a limit switch I20 (see Fig. 1)which is preferably of the normally open type and arranged to beactuated by the reproduclng tone arm II when the reproducing device l0has been caused to traverse all of the material recorded on one of therecord tablets means of a conductor I22 to one terminal of"a"""'' resetsolenoid I23 associated with the indicating device 23, the otherterminal thereof being connected to ground through a circuit I24 whichineludes the previously described cam switch 62.

It will be observed that conductor I24 will be connected to groundwhenever a coin has been inserted in the coin collecting device 3 tocause the registration by the indicating device 23 of a number ofmonetary value units. It will be remembered also that as soon as theactual operation of moving the indicating device 23 to its properindicating position has been completed, the relay 44 is de-energized soas to close its normally closed contacts and connect the conductor l2lto the control bus 50. It follows then that.as soon as the reproducingdevice I0 has been caused to traverse all of the recorded material onthe record tablet 9 to close the contacts I'20, the reset solenoid I23will be energized.

The manner in which the energization of the solenoid I23 operates todeduct one monetary value unit from the number of monetary value unitsindicated by the indicating device 23 may be best understood by havingreference to Figs.

7, 8 and 9. The solenoid I23 is preferably constructed in a manneridentical to the-indicating solenoid 48 previously described and issimilarly provided with an armature I25 carrying an operating springI26. The solenoid I23 and its associated mechanism is disposed on theopposite side of the toothed wheel 55 and arranged to cooperatetherewith in a manner identical to the previously described actuatingsolenoid 48.

It will be observed that the disposition of the reset solenoid I 23 onthe opposite side of the toothed wheel 55 causes its operation to resultin a reverse rotation of the toothed wheel 55 relative to the rotationimparted to it by the indicating solenoid 48. It is apparent then thatenergization of the solenoid I23 in the manner previously described willcause the toothed wheel and the pointer 25 secured to the pointer shaft53 to be moved back one notch to indicate on the scale 24 one lessmonetary value unit.

It will be further apparent that as soon as the same number ofphonographic recordings have been reproduced as were represented by thenumber of monetary value units indicated by the dial 24, the cam switch62 will be opened and will in this fashion extinguish the warning light22. The darkening of the warning light 22 then apprises the centralstation operator that all of the phonographic recordings which have beenpaid for have reproduced and that no more recordings should bereproduced until additional coins are collected by the coin collectingdevice.

In case it is desired to keep a visual record of the total value of.cains collected by each coin collecting. zdevice, a suitable counter orregistering ,dev'ice I 21 of a well known type may be mounted on theback of the mounting plate 52 of the indicating device '23 in a positiondisposed above the adjusting nut 58 of the indicating solenoid armature51, this position being illustrated-by dotted lines in Figs. 7 and 8. Anoperatin'g' arm I28 of the registering device I=2'I may be connected tothe upper end of the armature 51 by means of a suitable connecting linkI29 so that each operation of the indicating solenoid 48 in accordancewith the number of monetary value units collected by the coin collectingdevice 3 will cause each such unit to be. permanently registered by theregistering device I21.

'-- -:-;Iti-;wll1 be apparent that this registration is.

permanent and is not effected by the reset solenoid I23 as is theindicated value indicated by the dial 24 and pointer'25.

Attention is called to the fact that the coin collecting device and thecentral station coin indicator are always maintained in an operativecondition regardless of whether or not the equipment is actuallyreproducing phonographic recordings.

While we have described the foregoing equipment in terms of operationsperformed at one of the six control stations illustrated, thedescription is to be understood to apply as well to any one of thesestations since we intend that each of the control stations and each ofthe groups of equipment which is located at the central station anddefinitely associated with a control station be constructed in a manneridentical to that just described and interconnected in an identicalmanner. It will be observed that the control conductors TI and I00 whichconnect to the se-' lector device 28 are assigned only to the particularcontrol station about which the previous description has centered. Weprovide corresponding pairs of conductors associated with each of theother control stations which are connected trolling equipment will beconnected into the circuits extending to the selected control station ina manner identical with that previously described.

While the operation has been described in connection with but one of thecontrol stations, it is apparent that the use of independent coinindicating devices and reproducing equipment in connection with thepreviously described control, transfer, and selector devices permits thesimultaneous reproduction of diiferent phonographic recordings at anynumber of control stations. We have shown and described the system ofour invention as employing six control stations, but comprehend the useof more or less as conditions may require, there being employed one setof reproducing and coin indicating equipment and one position on theselector means 28 for each of the stations so connected.

While we have shown and described the preferred embodiment of ourinvention, we do not desire to be limited to any of the details of construction shown or described herein, except as defined in the appendedclaims.

We claim:

1. In a sound reproducing system, the combination of: a central stationhaving a plurality of reproducing units thereat, each of which includesa reproducing means for reproducing previously recorded material from arecord tablet; a plurality of control stations, one for each of saidreproducing means, situated remotely from said central station andhaving sound producing means thereat; means connecting each of saidsound producing means to its associated reproducing means forreproducing at said control station previously recorded materialreproduced by the associated reproducing means; manually operablecontrol means at each of said control stations; an indicating means atsaid central station for each of said control means responsive tooperation thereof for indicating to an operator at said central stationoperation of the associated control means; sound responsive means atsaid central station; selector means at said central stationforselectively connecting said sound responsive means to any one of saidsound producing means; another sound responsiv means at each of saidcontrol stations; another sound producing means at said central station;and transfer means at said central station cooperating with saidselector means and operable by said operator for connecting said soundresponsive means to said sound producing means selected by' saidselector means and for connecting said other sound responsive means tosaid other sound producing means, whereby telephonic communication isestablished between said operator and a person at said control station.

2. In a sound reproducing system, the combination of: a central stationhaving a plurality of reproducing units thereat, each of which includesa reproducing means for reproducing previously recorded material from arecord tablet; a plurality of control stations, one for each of saidreproducing means, situated remotely from said central station andhaving sound producing means thereat; a single circuit means connectingeach of said sound producing means to its associated reproducing meansfor reproducing at said control station previously recorded materialreproduced by the associated reproducing means; manually operablecontrol means at each of said control stations connected to said singlecircuit means; an indicating means at said central station for each ofsaid control means connected to said single circuit means and responsiveto operation of said associated control means for indicating to anoperator at said central station operation of said associated controlmeans; sound responsive means at said central station; and selectormeans at said central station for selectively connecting said soundresponsive means to any one of said single circuit means to actuate theassociated sound producing means, whereby said operator may acknowledgeverbally the operation of a control means at any selected one of saidcontrol stations.

3. In a sound reproducing system, the combination of acentral stationhaving a plurality of reproducing units thereat, each of which includesa reproducing means for reproducing previously recorded material from arecord tablet; a plurality of control stations, one for each of saidreproducing means, situated remotely from said central station andhaving sound producing means thereat; a single circuit means connectingeach of said sound producing means to its associated reproducing meansfor reproducing at said control station previously recorded materialreproduced by the associated reproducing means; manually operablecontrol means at each of said control stations connected to said singlecircuit means; an indicating means at said central station for each ofsaid control means connected to said single circuit means and responsiveto operation of said associated control means for indicating to anoperator at said central station operation of said associated controlmeans; sound responsive means at said central station; selector means atsaid central station for selectively connecting said sound responsivemeans to any one of said single circuit means to actuate th associatedsound producing means; another sound responsive means at said controlstation; another sound producing means at said central station; andtransfer means at said central station cooperating with said selectormeans and operable by said operator for alternately connecting saidsound responsive means and said other sound pro ducing means to the oneof said single circuit means selected by said selector means, wherebytelephonic communication is established between said operator and aperson at said control station.

4. In a sound reproducing system having a central station, a controlstation situated remotely from said central station, and means operableby an operator at said central station for reproducing previouslyrecorded material at said control station for pay, the combination of:coin collecting means at said control station responsive to collectionof a coin for producing a signal for each coin collected; means fortransmitting to said central station signals produced by said coincollecting means; and a registering means at said central station forreceiving and registering said signals and indicating to said operatorthe number of coins collected by said coin collecting means.

5. In a sound reproducing system having a central station, a pluralityof control stations situated remotely from said central station, and aplurality of reproducing means at said central station operablyassociated with said control stations and operable by an operator forreproducing previously recorded material at the associated controlstation for pay, the combination of: coin collecting means at each ofsaid control stations responsive to collection of a coin for producing asignal for each coin collected; means for transmitting to said centralstation signals produced by said coin collecting means; and anindicatcorded on said record tablet.

W AvmABLE 00px lq bgusi n 15 .I.

V I ami s 75 microphone and said loud speaker to said phonographicreproducer; a control microphone and a monitor loud speaker at saidcentral station; a pair of separate volume control units associated withsaid monitor loud speaker; and a three. position switch meanscooperating with said monitor loud speaker and said control microphoneand operable in a first position to connect said control microphone tosaid circuit means and operable in a second position to connect saidmonitor loud speaker and one of said volume control units to saidcircuit means and operable in a third position to connect said monitorloud speaker and the other of said volwho control units to sai ci cu mel= In a sound reproducing system. t e co bination oi; a ati n; a plur iy o control stations situat r m l fro said; central station and each havg a oud sp k r and a microphone; tiroult means nnectin the loud speaks?and microphon at each c nt I station to said central station: a oceano rphic rcnroiuccr at said central sta 01" eac 0011- trl s ation connectedto the c u t ans associated therewith tor re roducing phouogranhirecordings at the associated contro a a control micro hone and a monitorloud speaker at said central station; and a sel means at said centralstation lot telsttivtlr c i said control microphone and said monitorscatter to said selected circuit ne to ovide a twcwar loud spe ing telph i t tstwttn said tsntrsl staand th nt l a tics tottesnondinfl to addelecte circuit n it: n assassinated tics sy tem, the mb nation o acentral stat n1 ha a p u ty 9! reproducin units thetea c of which nfiQi'QElBPlilfi eans to; renrod cins a.v r s y rttcrsis m tatist; a sltl tr r c rial from 'a record u 91 stations s t tmctelr item s ld tt istat o and having Rlllii-l statist cs moans thsrsat; n w r a tint sash aield sound Produ means to a iitFQFl-llillfi m? I OQWW at said ttol stttti ever! reterslsd material repro- QHGFQ P? M8 FPF-IHP1H8 3 2%; r windproduct; g means at said central station; and

tclsttcr mea at sai cent al station for selectively connecting saidother sound producing moms to any at sa d rsnt qst ns mean t {EH99 o attats tssttsl statics th same m srls that is rssmtlttssl at th nt l, st ttccnsttsd to tilt stlettstl metastasis means,

it in a some retreats s s stole tbs =9 titasies ct; FiiilFFfi! st clFFBFHQHPiHE units the, t r; r it includes a relatedness m ss t e rod ipreviousl retarded materiel mm a tt rd let; a Blt allty 9isssttelststloas sit a d r msttlr tram said tssttsl s on and h rms smmristatistics masts thr t; m ans t csttins sash oissltl solute at waist mns o s FfiRlFlilHPlilE mean #9, tsrt sin at d 1- irql stat csnrtvloilslr reta ded mat reprotlrts l tr said FtPFQFlHFiFl me n ma llststls testml m ns at stat o said con ol tiers; an ictli tiss me ns atsai central ratios FFBQH1V9E9 ossrstlcc at e o said control means torimitating to an operator at said ssnt sl statio operation o any saidcontrol ns; l ts'mrtire means at said central salon; sat selector wa t asaid tral station tor selectively connecting said sound responsive meansto any of said sound producing means, whereby said operator mayacknowledge verbally the operation of a control means at any selectedone of said control stations.

16. In a sound reproducing system, the combination of: a centralstation; a plurality of control stations situated remotely from saidcentral station and each having a loud speaker and a microphone; circuitmeans connecting the loud speaker and microphone at each control stationto said central station; a plurality of phonographic reproducers at saidcentral station; means for connecting said reproducers to said circuitmeans for reproducing phonographic recordings at the control stationsassociated with the circuit means to which said reproducers areconnected; as control microphone and a monitor loud speaker at saidcentral station; and a selector means at said central station forselectively connecting said control microphone and said monitor speakerto any of said circuit means to provide a two=way loud speakingtelephonic circuit between said central station and any of said controlstations,

17. In a sound reproducing system, the combination of: a central stationhaving a plurality of reproducing units thereat, each of which includesa reproducing means for reproducing previously recorded material from arecord tablet; a plurality of control stations situated remotely fromsaid central station and having sound producing means thereat; means forconnecting each of said sound producing means to a reproducing means forreproducing at said control station previously recorded materialreproduced by said reproducing means; manually operable control means ateach of said control stations; an indicating means at said centralstation respgnsive to operation of each of said control means forindicating to an operator at said central station the operation of anyof said control means; sound responsive means at said central station;selector means at said central station for selectively connecting saidsound responsive means to any of said sound producing means; anothersound responsive means at each 01 said control stations; another soundproducing means at said central station; and transfer means at saidcentral station cooperating with said selector means and operable y doperator or coti ti g sai s un respons v llfifl-llsi to sa d sou doducin means ec b said s lect r mean n for nettins said tit soundFGQPQQQIY DEG- 745 f4) sa l the sca 9 tlllitillg means wh e- Phoniccommunication is established tween said operator and a person at saidcontro station.

t.- n a sound rsnrodu ins System. the bin n oi; a central sta ion h inaa al ty o rtnroduticg units eac o hich in? ud s a eproducing means torre o u ins nrev o rlv recorded material tram record t e a plurality oicontrol stations situated remotely means for indicating to an operatorat said central station the operation of any of said control means;sound responsive means at said central station; and selector means atsaid central station for selectively connecting said sound responsivemeans to any of said single circuit means to actuate the associatedsound producing means, whereby said operator may acknowledge verballythe operation of a control means at any selected one of said controlstations.

19. In a sound reproducing system, the combination of: a central stationhaving a plurality of reproducing units thereat, each of which includesa reproducing means for reproducing previously recorded material from arecord tablet;

and said central station; means associated with said circuit means forconnecting each of said sound producing means to a reproducing means forreproducing at said control station previously recorded materialreproduced by said reproducing means; manually operable control means ateach of said control stations connected to said single circuit means; anindicating means at said central station coupled to said circuit meansand responsive to operation of each of said control means for indicatingto an operator at said central station the operation of any of saidcontrol means; sound responsive means at said central station; selectormeans at said central station for selectively connecting said soundresponsive means to any of said single circuit means to actuate theassociated sound producing means; another sound responsive means at eachof said control station-s; another sound producing means at said centralstation; and transfer means at said central station cooperating withsaid selector from said central station and having sound pro' ducingmeans thereat; means for connecting each of said sound producing meansto a reproducing means for reproducing at said control stationpreviously recorded material reproduced by said reproducing means;manually operable control means at each of said control stations; anindicating means at said central station responsive to operation of eachof said control means for indicating to an operator at said centralstation the operation of any of said control means; signal producingmeans at said central station; and selector means at said centralstation for selectively connecting said signal producing means to any ofsaid sound producing means, whereby said operator may acknowledge theoperation of a control means-at any selected control station.

21. In a sound reproducing system, the combination of a central station;a control station situated remotely from said central station; a singleelectrical circuit extending between said central station and saidcontrol station; means operable by an operator at said central stationfor transmitting over said electrical circuit and reproducing at saidcontrol station previously recorded material; communication means atsaid central station and communication means at said control stationcoupled to said single electrical circuit for providing two-waycommunication between said stations over said single circuitsimultaneously with the transmission of preyiously recorded material;and means associated with said communication means for preventing inter-Ierence between said communication and the reproduction of previouslyrecorded material transmitted over said circuit simultaneously with saidcommunication. 4

22. In a sound reproducing system having a central station, a controlstation situated remotely from said central station, and means op erableby an operator at said central station for reproducing previouslyrecorded material at said control station for pay, the combination of:coin collecting means responsive to collection of a coin for producing asignal for each coin collected; means for-transmitting said signal tosaid control station; transmitting means interconnecting said centralstation and said control station for transmitting to said centralstation signals received at said control station; and a regisl

